..It is speculated that drug addiction results from the impact exerted on behavior by the abnormal DA stimulant properties acquired by drug-conditioned stimuli as a result of their association with addictive drugs...

Differential impact of pavlovian drug conditioned stimuli on in vivo dopamine transmission in the rat accumbens shell and core and in the prefrontal cortex

Valentina BassareoDepartment of Toxicology and Center of Excellence for Studies on Dependence, University of Cagliari, Cagliari, ItalyPsychopharmacology (Berl) 191:689-703. 2007

..Conditioned stimuli (CSs) by pavlovian association with reinforcing drugs (US) are thought to play an important role in the acquisition, maintenance and relapse of drug dependence...

..These results suggest that strain-related differences in the sensitivity of mesolimbic dopamine transmission to nicotine might be involved in the reported differences in the reinforcing effect of nicotine in Lewis and Fischer 344 rats...

Differential adaptive properties of accumbens shell dopamine responses to ethanol as a drug and as a motivational stimulus

..0 mg/kg), to the highest dose of amphetamine (1.0 mg/kg) and to all doses of cocaine. These differences might be the basis for the different behavioral responses of these strains to drugs of abuse...

Role of dopamine D(1) receptors in caffeine-mediated ERK phosphorylation in the rat brain

Elio AcquasDepartment of Toxicology, University of Cagliari, I 09124 Cagliari, ItalySynapse 64:341-9. 2010

....

Influence of morphine sensitization on the responsiveness of mesolimbic and mesocortical dopamine transmission to appetitive and aversive gustatory stimuli

..Although passive administration of heroin to drug-naive rats increases extracellular dopamine (DA) in the nucleus accumbens (NAc), its ability to do so also after active drug exposure (self-administration) is debated...

..Sensitization of the incentive and dopamine (DA) stimulant properties of drug-conditioned stimuli (CSs) by repeated exposure to drugs of abuse has been assigned an important role in the genesis of drug addiction...

..Drugs of abuse and palatable food share the ability to stimulate dopamine (DA) transmission in the nucleus accumbens shell. However, while the stimulation of shell DA by food undergoes habituation, that by drugs of abuse does not...

Liliana SpinaDepartment of Toxicology, Centre of Excellence for Studies on the Neurobiology of Addiction, University of Cagliari and Institute of Neuroscience, Consiglio Nazionale delle Ricerche, Cagliari, ItalyPsychopharmacology (Berl) 184:447-55. 2006

..However, the role of DA transmission of the two main subdivisions of the nucleus accumbens (NAc), the shell and the core, in the motivational properties of nicotine is unknown...

Preferential increase of extracellular dopamine in the rat nucleus accumbens shell as compared to that in the core during acquisition and maintenance of intravenous nicotine self-administration

..2 mg/kg was not significantly different in the shell compared to the core of nucleus accumbens. This study extends to MDMA the property of other drugs of abuse to increase preferentially nucleus accumbens shell dopamine...

..These observations indicate that DA responsiveness is an integrated function of the motivational valence and novelty of stimuli in the NAc shell and an expression of generic motivational value in the NAc core and PFCX...

Long-term increase in GAD67 mRNA expression in the central amygdala of rats sensitized by drugs and stress